A white amorphous A on heating yields a colourless, non-combustible gas B a solid C .The latter compound assumes a yellow colour on heating and changes to white on cooling C dissolve in dilute hydrochloric acid and the resulting solution gives a white precipitate with `K_(4)Fe(CN)_(6)` solution .A dissolve in dilute HCI with the evolution of gas , which is identical in all respect B turns lime milky , but the milkiness disuppears with the contimous passage of gas solution of A as obtained above gives a white precipitate D on the addition of excess of `NH_(4)OH` and passing `H_(2)S` another portion of the solution gives initialy a white precipitate E on the addition of NaOH solution , which dissolves on further addition of base , identify the compounds A,B,C,D and E `